This project seeks to identify in situ changes in central alpha receptor sensitivity in rats that may occur upon chronic ethanol administration. Electrophysiological techniques, e.g. microiontophoresis and single unit recording, will be utilized to study alpha (Alpha1 & Alpha2) receptor sensitivity. Receptor sensitivity will be studied at identified neurons (nucleus locus coeruleus and dorsal lateral geniculate nucleus) in the CNS. Such studies will provide evidence for physiological changes in receptor sensitivity that may occur upon chronic ethanol administration and might suggest newer pharmacotherapeutic approaches.